Insurgent attacks on U.S. troops supporting ongoing operations for the Global War On Terrorism (GWOT) in Iraq and Afghanistan have exposed vulnerabilities of the ground vehicles used by our troops. Consequently, the HMMWV (commonly known as HumVee) and other light tactical military vehicles, including the Light Utility Vehicle testbed by MillenWorks, are being up-armored to counter the insurgent threats and provide an increased level of soldier protection. A new issue results in that the additional weight of the armor and associated upward shift in center of gravity (CG) has caused these vehicles to become increasingly unstable and difficult for the troops to control. Numerous rollover accidents have and continue to occur given the tendency of these vehicles to go out of control and tip during evasive maneuvering, off-road travel and IED/RPG attack. When an up-armored vehicle rolls over, many times the crew cannot egress via the doors due to the weight of the armor on the doors, or jamming of doors from the vehicle frame twisting. The gunner's station is not an option for exit either if the vehicle is up-side-down. The result is that the crew is often killed due to vehicle fires, follow-up insurgent attacks, trauma injuries and drowning. Therefore there is a need for an emergency egress system for the up-armored vehicles.
A number of prior art examples exist with regards to emergency egress systems for vehicles. U.S. Pat. No. 3,739,527, issued Jun. 19, 1973, entitled KNOCKOUT WINDOW FOR VEHICLE, discloses a knockout window for a vehicle, such as a bus or mass transit car, U.S. Pat. No. 4,635,396, issued Jan. 13, 1987, entitled BUS WINDOW RELEASE MECHANISM, discloses a release mechanism for a vehicle, and U.S. Pat. No. 6,164,715, issued Dec. 26, 2000, entitled EMERGENCY EXIT WINDOW OF A VEHICLE WITH A WINDOW PANEL, discloses an emergency exit window of a vehicle. However, these prior art examples involve mechanisms that are incompatible with the transparent armor assembly required by military vehicles. The egress architecture must provide the crew the required level of blast protection while still meeting the unique interface and support structure requirements for the transparent armor assembly.
A standard (prior art) M1114 window armor assembly 8 is illustrated in prior art FIGS. 1 and 2. Window frame 10 provides the supporting structure for a window armor frame 12 and the two pieces of transparent armor (ballistic glass) 14. Window frame 10 defines an aperture for window spacer/sill 16 and transparent armor 14. The window armor frame 12 is disposed about the periphery of the transparent armor 14. The window armor frame 12 generally includes six separate armor plates: upper window armor plate 18, center armor plate 20, side armor plates 22 and the lower window armor plate 24. The window armor frame 12 overlies portions of both pieces of transparent armor 14 as at overlap 15, thereby capturing the transparent armor 14 in the frame 10. The individual plates, i.e. upper window armor plate 18, center armor plate 20, side armor plates 22, and lower window armor plate 24 of the window armor frame 12 are fastened by screws or similar type fasteners that extend into the windshield frame 10. The window frame 10 is fitted to the vehicle side armor 19. In an emergency situation, removal of transparent armor 14 is not possible by the occupant as the transparent armor 14 is secured by the window armor frame 12 from the exterior of the vehicle. Someone outside the vehicle would have to remove all of the fasteners of the window armor frame 12 before accessing the transparent armor 14, a time consuming operation that needlessly exposes the person performing the operation under combat conditions.
There is therefore a need for an improved alternate or additional egress capability for up-armored vehicles to address the previously described problem, especially the capability for the vehicle occupants to effect the egress without exterior assistance.